Ma ai literally means "harmony of space" and the meaning is fitting for the spirit of aikido. Ma ai in aikido generally refers to proper distance from an attacker, but the notion of maintaining a sense of harmony with space is a good way to find proper ma ai.
In its simplest sense, ma ai is the space that allows you to be safe. But ma ai changes as an attack occurs. While you don't want to be standing within your partner's sphere of influence before an attack (since he can easily strike and hit you), once the attack occurs, your relationship (your ma ai) changes dramatically. Because aikido responses almost always use blending, entering, or turning, you will find yourself very close to your partner. Don't panic! In aikido, as in love, close is good.
Distance is the enemy
The natural tendency is to put distance between us and something out to get us. In aikido, the opposite is true. Distance is the enemy in the aikido scheme of things. This is true for a number of reasons.
Distance leaves you open and draws your partner's ki into you. If you are the object of an attack, your distance requires your attacker to come to you. It draws your attacker's ki to your center. In more advanced practice you can use this to your advantage, but as you are learning about ma ai, think of distance as the bad guy.
Distance gives your partner room to attack
If your partner has sufficient distance between himself and you, he has room to wind up with a strong strike or kick. When you're in close, there is not nearly the same amount of room to wind up. For most striking and kicking attacks, this significantly reduces the effectiveness of the attack. Realize, however, that there are certain styles of martial arts that excel in close-in fighting techniques, so this isn't a sure defense in itself.
Distance breaks the connection
Since the essence of aikido is to join with your attacker's spirit, when there is distance, it is harder to maintain a connection. Being close to your partner allows you to make contact and keep a good connection. This connection transmits your partner's intent and actions to you.
Harmony is intimate
Strangely, to blend with an attack, the proper ma ai often puts you into an intimate relationship with your attacker. To enter in close and make the necessary connection often means allowing another person into a very close proximity to you. This close proximity can feel, and in fact is, very intimate.
It's important to understand that while aikido is intimate, this does not mean sexual. Even given that, many students still find this intimacy threatening or disturbing. Yet it almost can't be otherwise if you are "becoming one" with your attacker. Learning to allow a person, who may be trying to end your life, in close is, needless to say, one of the great challenges of aikido.
